Honeywell HA40 Name / Eunits Ascii Data Fields, Input Measurement Range, Decimal Point Resolution

Name / Eunits ASCII Data Fields

The first two items in this menu are for entering the 10 character channel Name and engineering unit ASCII fields. Name should describe the channel’s data in user terminology such as tag # or other description. Eunits should define the units of measure for what this channel is to display. Section 2.6 describes how to modify these fields using the keypad.

Input Measurement Range

The Zero / Span menu options allow configuration of the measurement range displayed by this channel. Measurement Range defines the range of the input signal’s engineering units. For example, if a channel’s input is 4-20mA from a transmitter monitoring 0 to 10ppm chlorine, then the Zero value should equal 0.000 and the Span value equal 10.00. Four digits must be entered so trailing 0’s may appear here that are not displayed on other data screens. These menus work hand in hand with the Min/Max Raw Counts menus described in section 2.7.4.

Decimal Point Resolution

Resolution of the displayed channel value is configured in the Decimal Pts. menu by setting the number of digits trailing the decimal point. Displayed readings are limited to a maximum of four digits with a polarity sign. Auto-ranging displays the highest resolution allowed by this menu’s decimal point entry. For example, a range of 0 to 100ppm and two decimal points reads 0.00 at 0ppm and 100.0 at 100ppm. This may be undesirable due to the high resolution at zero unless the sensor’s output is extremely stable. If decimal points are limited to one, the 0ppm reading becomes 0.0 and the 100ppm reading remains

100.0.Resolution may be limited further by setting decimal points to 0 where in the above example, 0ppm reads 0 and 100ppm reads 100.

Turning Off Unused Channels

The Channel Active menu option asks if this channel is to be utilized. NO causes the controller to never process inputs applied to this channel and no alarms are tripped or data displayed. Inactive channels have a line drawn through them on the Setup screen to indicate they are turned off.